Tuesday, January 28, 2014

Loads of insects use the creosote bush in some way. The larvae of a species (or two) of creosote gall midge, for example, live in the leafy ball-like galls pictured below. The female midge fly deposits her eggs in the stem. (Other species deposit other places.) The plant produces the gall to heal the 'wound;' the eggs hatch and the larvae say: yum.

Photo by Ned Harris - This gall is relatively 'fresh'

Photo by Ned Harris - Same kind of gall, but dried out.

Other species of midge lay eggs in different areas/parts of the creosote bush. The corresponding galls look different. The gall below looks like it's composed mainly of crystallized sap.

Monday, January 27, 2014

On Ned's nature walk, we saw a number of piles of fresh dirt with no visible opening or hole. The ever-helpful visitors asked: "Who makes these piles?" And Ned was able to tell them about Botta's Pocket Gophers.

Photo by Ned Harris, Mt Lemmon 7/10/2013

You don't often see these little guys, because they spend most of their time underground. You may only see a tug-tug-disappearing plant as they pull vegetation into their burrows. (I've witnessed that and, after recovering from being startled, it was pretty amazing to watch.)

Beth of Firefly Forest writes:

Botta's Pocket Gophers and other Pocket Gophers leave a fan-shaped dirt mound in front of their burrows, and the burrow entrances are usually kept securely closed up with dirt. Even though they live in areas with many others of their own kind nearby, Botta's Pocket Gophers are solitary and territorial, and they will fight any other gopher that dares invade their burrow.

Sunday, January 26, 2014

We spotted this bobcat coming out of a road culvert across from Sabino with another bobcat about two-thirds her size, probably her kitten. Mom paused to see if we would follow. Interesting thing: though bobcats are the most common wildcat in North America, a sighting in most of the U.S. is a rare thing. We’re lucky here in Tucson to see them as often as we do.

Friday, January 24, 2014

The splits in the saguaro 'skin' are the result of freezing. Water expands when it freezes, as you know. And when water freezes in a cactus, the skin can only expand so far before it splits. The saguaro can live a long time after this kind of damage, provided it's not too extensive.

Photo by Ned Harris 1/8/2014

Idiots caused this damage. You can see rocks embedded in this saguaro. (If I were queen, there would be a lot more beheadings.)

Photo by Ned Harris, hand by Lyn Hart 1/8/2014

The only animal who can make a cut like this is a human with a knife or a machete. See note above about beheadings.

And finally, my post "Prickly Pear Theories" caused a bit of confusion. Some people thought that damage was caused by (or actually was) cochineal. Nope. (And nope.) The damage might not have been intentional, but it was caused by rocks. You see prickly pears with pressure damage along the road and along trails that get a lot of traffic. Small rocks get kicked up (or picked up). Yes, the cochineal insect does feed on the prickly pear, but even a big infestation wouldn't cause that damage. More info on cochineal.

Thursday, January 23, 2014

You often see saguaros of the same relative size in a group like this (called a cohort). If saguaro seeds fall (i.e., get pooped out) in a good location (e.g., under a mesquite tree) at a good time, they may sprout. If the sprouts don't get eaten, trampled, fried, or frozen, they may just make it past the first decade. If they make it past the first decade, (and most do not) they may make it another decade.

Wednesday, January 15, 2014

People often ask: Why are horses allowed in Sabino Canyon, but not dogs? There are a number of reasons, but one has to do with diet. Horses are herbivores. [Yes, those big, strong creatures get all the energy (and the protein) they need from plants and only plants.] Dogs, like coyotes, are omnivores. And, as you know, you poop what you eat. Horse poop doesn't smell appealing to carnivores like mountain lions and bobcats. Dog poop does. And, let's face it, not every dog walker is as responsible as you about picking up.

Thursday, January 9, 2014

Jojoba (Simmondsia chinensis) is one of the relatively few flowering plants that has separate sexes. Most flowering plants have both male and female parts on the same flower; some have separate male and female flowers. But Jojoba has male plants and female plants. How cool is that?

All Photos by Matt Ball 1/4/2014

Both photos above show the male plants. If you see clusters of rather nondescript greenish flowers, then you're looking at a male plant.

The female flowers are never in clusters. The two photos above show female flowers. Now you, too, can amaze your friends and family!